Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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- Definition

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
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-Section S99
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- Definition

Amount of investments in debt securities classified as available-for-sale, expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 25
-Paragraph 1
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- Definition

+ References

+ Details

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- Definition

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.5-02.1)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. For a classified balance sheet represents the current portion only (the noncurrent portion has a separate concept); there is a separate and distinct element for unclassified presentations.

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- Definition

Cash and equivalents whose use in whole or in part is restricted for the long-term, generally by contractual agreements or regulatory requirements.

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Fair Value Measurements - Summary of Cash and Cash Equivalents and Short Term Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, amortized cost and estimated fair value	$ 1,800	$ 14,034
Cash and cash equivalents, amortized cost and estimated fair value	15,233	34,310	$ 27,897	$ 14,593
Restricted cash, amortized cost and estimated fair value	272	272
Amortized Cost	10,231	20,885
Gross Unrealized Losses	(1)	(9)
Estimated Fair Value	10,230	20,876
Restricted cash, amortized cost and estimated fair value		272
Money market securities [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, amortized cost and estimated fair value	11,931	20,276
Restricted cash, amortized cost and estimated fair value	272
Restricted cash, amortized cost and estimated fair value		272
Corporate bonds and commercial paper (cash and cash equivalents) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, amortized cost and estimated fair value	1,502
Corporate bonds and commercial paper (short term investments) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	8,231	20,885
Gross Unrealized Losses	(1)	(9)
Estimated Fair Value	8,230	$ 20,876
Government securities [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	2,000
Estimated Fair Value	$ 2,000